A234278 The number of circular maps C(n) with n edges regardless of genus.

1, 2, 5, 16, 56, 333, 2147, 17456, 158022, 1604281, 17863089, 216774585, 2844162968, 40129498111, 605894465441, 9748493596584, 166520626541070, 3009885559478844, 57397289146583917, 1151666341035710396

Offset: 1

Author

N. J. A. Sloane, Dec 28 2013, based on email from Madina Deryagina and Alexander Mednykh

Keywords

• nonn

Comments

The circular maps are also the maps whose faces could be colored in two colors.

Links

• M. A. Deryagina and A. D. Mednykh, On the enumeration of circular maps with given number of edges, Siberian Mathematical Journal, 54, No. 6, 2013, 624-639.
• M. Deryagina, On the enumeration of hypermaps which are self-equivalent with respect to reversing the colors of vertices, Preprint 2016.

Formula

See formula for C(n) in Theorem 2.1 of Deryagina and Mednykh (2013).